Re: [PATCH 1/2] docs/about: Deprecate 32-bit x86 hosts and qemu-system-i386

On Mon, Feb 27, 2023 at 10:21:14AM -1000, Richard Henderson wrote: > On 2/27/23 10:12, Michael S. Tsirkin wrote: >> On Mon, Feb 27, 2023 at 11:50:07AM +0000, Daniel P. Berrangé wrote: >>> I feel like we should have separate deprecation entries for the >>> i686 host support, and for qemu-system-i386 emulator binary, as >>> although they're related they are independant features with >>> differing impact. eg removing qemu-system-i386 affects all >>> host architectures, not merely 32-bit x86 host, so I think we >>> can explain the impact more clearly if we separate them. >> >> Removing qemu-system-i386 seems ok to me - I think qemu-system-x86_64 is >> a superset. >> >> Removing support for building on 32 bit systems seems like a pity - it's >> one of a small number of ways to run 64 bit binaries on 32 bit systems, >> and the maintainance overhead is quite small. > > It's not that small. It only works for single-threaded system mode. It > silently does not honor atomicity for user-only mode, which is perhaps worse > not working at all.

We should probably block multi-threading on 32 bit then.